[X] My Assistant

[djellison]

Look at the MI campaign on this puppy It's got to be a 4 x 4 frame MI mosaic

http://qt.exploratorium.edu:16080/mars/spi...cam/2005-04-28/

Doug

[Burmese]

I wonder how this rock picked up that tidy circular impression?

http://marsrovers.jpl.nasa.gov/gallery/all...I4P2564L7M1.JPG

[dvandorn]

I wonder how this rock picked up that tidy circular impression?

http://marsrovers.jpl.nasa.gov/gallery/all...I4P2564L7M1.JPG

There's always one good explanation for tidy circular impressions -- craters. In the absence of any other data, I'd guess it's a very small crater from a very small impactor.

I bet the rock is pretty soft or unconsolidated, though, to record a crater so nicely without being blown to bits by such an impact...

-the other Doug

[JRehling]

I wonder how this rock picked up that tidy circular impression?

http://marsrovers.jpl.nasa.gov/gallery/all...I4P2564L7M1.JPG

There's always one good explanation for tidy circular impressions -- craters. In the absence of any other data, I'd guess it's a very small crater from a very small impactor.

I bet the rock is pretty soft or unconsolidated, though, to record a crater so nicely without being blown to bits by such an impact...

-the other Doug

Any impactor small enough to make a crater that small would certainly have burned up in the martian atmosphere. This is the sort of impact feature that may exist on the Moon, but never Mars.

[Jeff7]

I wonder how this rock picked up that tidy circular impression?

http://marsrovers.jpl.nasa.gov/gallery/all...I4P2564L7M1.JPG

There's always one good explanation for tidy circular impressions -- craters. In the absence of any other data, I'd guess it's a very small crater from a very small impactor.

I bet the rock is pretty soft or unconsolidated, though, to record a crater so nicely without being blown to bits by such an impact...

-the other Doug

Any impactor small enough to make a crater that small would certainly have burned up in the martian atmosphere. This is the sort of impact feature that may exist on the Moon, but never Mars.

They've found what look like tiny craters at Opportunity's site. Sure, if it's tiny when it enters the atmosphere, the object will disintegrate quickly. But if it's large enough, a small portion of it could make it to the surface.

I place my bet that it's simply a random formation - just like how we see shapes in the clouds, we happened upon a formation that has a round imprint on it.